Vacuum operated switch



Aug. 4, `1936. J. w. WHITE VACUUM OPERATED SWITCH Filed June 6, 1954 INVENTOR.

Jol? n 144 /4//2 z' Z.

4W g, @ma mm A TTORNEYS.

Patented Aug. 4, 1936 UNITED STATES PATENT oFFIcE VACUUM OPERATED SWITCH JohnW. White, Detroit, Mich.

Application June 6, 1934, Serial No. 729,191

2 Claims.

This invention relates to electric switches particularly useful for controlling the circuit of stop lights of motor vehicles having vacuum operated brakes..

The main objects of this invention are to provide a vacuum or suction operated switch for use on. motor vehicles having vacuum or booster brakes; to provide a suction operated switch of extreme simplicity and low cost of manufacture;

to provide a switch in which a flexible diaphragm carries a bridge element which makes and breaks the circuit; to provide a iiexible diaphragm which may be attached to and removed from the switch body without the aid of tools or fastening means other than the diaphragm itself; to provide a switch having a diaphragm which is flexed by atmospheric pressure to move a bridge element carried thereby into circuit closing position and to open said circuit upon equalization of pres sures on both sides of the diaphragm; and to provide an electric switch in which the binding post terminals to which the circuit wires are attached also serve as contacts for the circuit closing bridge element.

An illustrative embodiment of this invention is shown in the accompanying drawing, in which- Fig. 1 is a view somewhat diagrammatic showing my improved switch in a stop light circuit and connected -to the intake manifold of an in ternal combustion motor of a motor vehicle;

- Fig. 2 is a top plan view of my improved switch;

Fig. 3 is a sectional view of the same taken on the line 3-3 of Fig. 2 looking in the direction indicated by the arrows;

Fig. 4 is a sectional view of the same taken on the line 4-4 of Fig. 3 looking in the direction indicated by the arrows;

Fig; 5 is a sectional view similar'to Fig. 3, but

with the diaphragm flexed so as to move the bridge element into circuit closing position.

In the construction shown in the drawing, an internal combustion motor, I0, is shown withan intake manifold II, to which is connected the manually controlled valve, I2, by a suitable pipe` or conduit, I3. The valve, I2, is connected by a pipe, I4, to a suction cylinder, I5, of brake operating mechanism, I6, which in the present illustration includes a master cylinder |6A of a.

hydraulic braking system connected to the four brake drums ISB of a vehicle.

My improved form of electric switch, generally designated in Fig. 1 vbv the numeral I 1, is connected to and communicates with the pipe,

I4, so that the switch is subjected to the suction (Cl. 20o-83) ing or body, 20, is provided with an axially disposed opening, 23, extending therethrough, and at the end adjacent the iiange, v22, is chambered 15 out to form an opening, 24, for receiving a cup- \shaped metallic circuit closing bridge member, '25. The member 25 is secured by a rivet 26, to

the center oi a disc-shaped exible rubber diaphragm, 21,*which constitutes one wall of the 20 opening, 24. The marginal edge of the diaphragm, 21, is beaded at 28', and provided with an interiorly disposed annular groove, 29, for receiving and snugly embracing the flange, 22, of the body housing. 25

The rim of the cup, 25, extends in loosely spaced relationship into a cylindrical groove, 30, formed in the opening, 24, concentrically with the opening, 23, and spaced outwardly therefrom.

The body or housing, 20, is also provided with a 30 pair of diametrically opposed, radial disposed screws, 3| and 32, threaded through the side Walls of the body, and extending into thelower part of the cylindrical groove 3U, in position to be contacted by the edge of the rim of the cup- 35 shaped bridge member, 25, when said bridge member is moved inwardly by flexing of the diaphragm when subjected to differential pressures on the opposite sides thereof.

The screws, 3| and 32, are adapted to receive 40 the terminals, 33 and 34, respectively of the electric circuit wires, thus serving the double funcr tion of binding posts and contact elements for the switch.

In the operation of this device, the iiexible rub- 45 ber diaphragm, 21, normally supports and maintains the cup-shaped bridge element, 25, in open circuit position, as shown most clearly in Fig. 3 of the drawing.

When the bore, 23, and opening, 24, are sub- 50 jected to suction by reason of the vacuum brake control valve, 2, being moved to its operative position, the atmospheric pressure on the outer side of the diaphragm, 21, will flex it inwardly s uciently to cause the rim edge of the cup- 55 shaped bridge element, 25, to rest upon and establish electrical communication between those portions of the screws, 3l and 32, which extend within the cylindrical groove, 30, thus closing the circuit to the stop light, l 9.

When the manual control valve, I2, is moved to its inoperative position, atmospheric pressure is again established in the conduit, I4, and within the bore, 23, and opening, 24, of the switch, at which time the flexible diaphragm, 21, will return to its normal position, thus opening the circuit.

Although but one specific embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim:

1. An electric switch comprising a body of dielectric material having an opening therethrough, a pairv of combined binding posts and electric contacts threaded into said body and extending into said opening, a flexible rubber diaphragm sealing one end of said opening, and a bridge,

member mounted on said diaphragm within said opening and arranged to close the circuit between said contacts when said diaphragm is flexed inwardly of the opening, the other end of said opening being adapted to be connected to a source uf suction for flexing said diaphragm to close the circuit.

2. An electric switch comprising a. body of dielectric material having an opening therethrough, an outwardly extending radially disposed flange on one end of said body, a pair of combined binding posts and electric contacts threaded into said body and extending into said opening, a flexible rubber diaphragm having an annular groove therein for embracing said body flange and sealing one end of said opening, a cup-shaped metal bridge mounted on said diaphragm within said opening and arranged to close the circuit between said contacts when said diaphragm is flexed inwardly of said opening, the other end of 2G said opening being adapted to be connected to a source of suction for llexing said diaphragm to close the circuit.

JOHN W. WHITE. 

